This invention relates to a process for the preparation of a row of two different and alternating types of drop wires for the automatic drawing-in of a warp for a weaving machine, in which the drop wire types each have a thread eyelet spaced the same distance from an end thereof, each have an identical elongated slot spaced the same distance from the other end thereof for the reception of a rack rail or a contact rail of a warp stop motion device on which the drop wires are adapted to hang, and each have a keyhole spaced from the thread eye in one of the types of drop wires a different distance than the spacing of a keyhole from the thread eye in the other of type drop wires, and wherein a lease rod is employed for displacement of a first the two types of drop wires along the longitudinal axes thereof until the keyholes of all the drop wires are aligned between drop wires to facilitate reception of a pin for the pinning of the drop wires.
This invention further relates to an assembly of two different and alternating types of drop wires prepared by the above process.
Thus, the invention relates to drop wires which are suitable for the automatic drawing-in of warps and which have for such purpose a keyhole near the thread eye in each drop wire, through which a rod or a round bar having a helical tip is passed so that the warp threads can thereby be drawn-in. The pinning of the drop wires can only take place when in the stack of drop wires the keyhole slots extend from the circular hole thereof upwardly for one type drop wire and downwardly from the other type drop wire. This so-called 1-1 pinning of the drop wires must first be arranged to facilitate the automatic drawing-in of warp threads.
The two drop wire types, which differ from one another according to whether the key hole slot extends upwardly or downwardly, also differ in that the distance of the key hole from its thread eye is greater for one drop wire type than for the other drop wire type. This distance of the key hole from the thread eye which, in all drop wires is located at the same distance from one drop wire end, is made deliberately larger, so that during mill operations the keyholes of the drop wires do not align with one another, since otherwise a strand of lint consisting of dust and fibers can easily form in a row of aligned holes, which can compromise the free mobility of individual drop wires, so that a predetermined operating readiness of the warp stop motion device cannot be assured.
In order to introduce the rod with its helical end into the keyholes required for the pinning of the drop wires, all those drop wires in a drop wire row hanging on an auxiliary rod must first be raised for those having the keyhole spaced a greater distance from its thread eye as compared to those remaining drop wires having the keyholes lying at a smaller distance from their thread eyes. If the correct 1-1 threading for pinning the drop wires in the drop wire row is already present, any other drop wire in the row must be raised up. However, since errors are usually encountered during preparation for automatic drawing-in of warp threads, it becomes necessary to add or reduce the number of drop wires, so that there is no assurance that a row of drop wires prepared for a device for automatic drawing-in of warp threads has the correct drop wire threading sequence in which a drop wire with a keyhole slot extending upwardly is alternately succeeded by a drop wire in which the slot extends downwardly. For the preparation of a drop wire row for automatic drawing-in of warp threads, two conditions must therefore be fulfilled, i.e., all drop wire keyholes must be aligned, and the correct 1-1 threading must be present.
According to the prior art as shown in FIGS. 1 and 2, the lower ends of both drop wire types 101 and 102 are provided with upwardly extending recesses 103 and 104 so that a row of alternating drop wires 101 and 102 can be arranged using a lease rod matching the depth of recesses 103 so that drop wires 102 with the shallower recesses 104 can be raised upwardly. Otherwise, as shown in FIGS. 3 and 4 according to a further prior art approach, drop wires 105 and 106 of both types have, at their elongated slots 107 and 108 through which the rack rail or contact rail of the warp stop motion device passes, rounded holes 109 and 110 formed in the edges of these slots. Holes 109 are located at different distances from thread eye 111 thereof as compared to the distance between holes 110 and thread eyes 112 thereof. Therefore, upon insertion of a pointed lease rod through holes 109 and 110, drop wires 106 will be raised relative to drop wires 105. However, because of holes 109 and 110 the drop wires can remain hanging on the rack rail, and with the differently sized recesses in the lower ends of the drop wires 101 and 102, the assembled drop wires do not function as well as intended, because the drop wires which lie close to each other in a row can stick to one another, in that sizing residue from the warp threads can cling to the drop wires. Thus, with this movement of the drop wires relative to one another there is no driving motion which is determined by form.